Sheet metal clamp



' 1942- I H. A. DUNCAN 2,281,421

v SHEET METAL CLAMP I Filed July 18, 1941 Arm/Mfr Patented Apr. 28, 1942 res T OFFICE 3 Claims.

metal sheets be subjected to identical treatment, especially in order that they may have a plurality of corresponding holes for riveting or other treatment, and as these holes must be in absolute alignment with each other, it is essential that these sheets be maintained in fixed abutment upon each other during the process of making holes, or openings, therethrough.

The usual method of accomplishing this desirable result is to bore, or punch, several holes in the sheets, usually along the marginal edges thereof, and then adopt some means for maintaining the sheets in fixed position with respect to each other, during the boring, or punching, of

the required number of aligned openings through the sheets thus maintained in abutment.

Various devices have been suggested for insertion through such placement holes in order that the metal sheets may b maintained in abutment position, and my invention relates to devices adapted for this purpose.

.Among the essential properties of a properly suitable device for the purpose mentioned are ease of insertion through aligned holes, ease of withdrawal therefrom, efiectiveness of abutmentretention of the sheets, adaptability for holes of different dimensions within limits and economy in production.

The device of my invention comprises two corresponding elements of the scissor-type of construction, one end of each such element being of elongated formation, the two elements being so pivotally connected that the extremities of such elongated members may be brought together to form a V-shaped device adapted to be passed through such aligned openings in' a plurality of metal sheets, and resilient means adapted to cause said elongated members to cross each other with their extremities pointing outwardly from each other and forming a four point pressure contact with the metal sheets.

The device of my invention, adapted for the above described, and other desirable properties, comprises, in a broad way, two corresponding elements, th one end portion of which is extended into an elongated member, referred to as a bite, the two elements being pivotally attached to each other between their end portions I, and carrying a spring so positioned as to naturally maintain the extended bites cross-wise of each other with their extremities pointing away from each other.

It is evident, therefore, that by pressing the biteless ends of the two pivoted members toward each other against the spring pressure, the ends of the bites can be brought to a common point, thus forming a V-shaped construction easily inserted through the aligned holes of a plurality of metal sheets, until the bites abut upon the sides of the holes, and that upon a release of the pressure, the bites are forced toward and across each other by the spring action thus forming a four-way compression of the bites against the metal sheets.

It will thus be seen that the sheet metal clamps of my construction are inexpensive of production, easy to operate, positive in action and adaptable to-holes of different diameters.

The novelty and advantages of the device of my invention will be evident upon a consideration of the accompanying drawing, in which similar parts are designated by similar numerals.

Figure 1 is a front view of one form of my device in normal position.

Figure 2 is a side View of the device of Figure 1.

Figure 3 is a side view of the device of Figure 1, with the handle ends pressed toward each other, causing the bites to meet at a common point for insertion through aligned holes in the two metal sheets shown in cross-section above my device.

Figure 4 is a side view similar to Figure 3, with the bites inserted through the holes in the two metal sheets and with pressure removed from the handle ends, the crossed-bites maintaining the two metal sheets in fixed abutment with each other.

The particular form of a sheet metal clamp shown in the accompanying drawing comprises the similar and corresponding body members Hi and 10', having the respective elongated bite ends II and H, the other end being twisted upon themselves forming the finger pressure, or handle, members l2 and I2.

The two body members I0 and ID are pivotally attached to each other by the bolt l3 and the ends M, M of the spring I5 pass through openings I6, I6 in the body members I0 and H), the spring being wound around the bolt 13.

The body member In carries the stop pin H adapted to enter the recess l8 of the body member ll! to limit the movement of the body members.

The normal positions of the elements of the clamps are shown in Figure 1, the bite ends ll and l I being crossed over each other and pointing outwardly from each other, and being maintained in that position by the action of the spring IS.

The operation of the device in clamping two sheets of metal l9 and 19' having respectively the openings 20 and 20 is shown in Figures 3 and 4.

The metal sheets 19 and [9' are abutted upon each other with their respective openings 20 and 20' in alignment with respect to each other.

The two finger ends I2 and 12 are pressed toward each other until the ends of the bites H and H are positioned near enough together to pass through the openings 20 and 20' of the metal plates I9 and I9, these bite ends are shown as touching in Figure 3, but this particular relationship is not absolutely necessary.

The bite ends are then passed through the openings 20 and 20' of the metal plates l9 and l9 and the pressure upon the finger ends l2 and I2 released, the device then being as shown in Figure 4.

It will thus be noted that the device has a fourpoint pressure contact with the two plates l9 and 19'.

The bite H has a downward-outward pressure to the right upon plate l9 and an upward-outward pressure to the left upon plate l9, while the bite H has a downward-outward pressure to the left upon plate I9 and an upward-outward pressure to the right upon plate I9, thus firmly maintaining the plates l9 and I9 into abutment position with their openings 20' and 2| in alignment with each other.

It will be further noted that each of my devices is adapted for use with metal plates of various diameter holes, as long as the diameters of the holes are such as to allow both bites to extend through both plates and allow them to be'positioned crossed-angularly with respect to each other.

It will thus be seen that the device of my invention is an effective, positive acting and inexpensive means for the clamping together of a plurality of metal sheets in order to allow of uniform treatment thereof.

' I do not limit myself to the particular size, shape, or arrangement of parts as shown and described as these are given solely for the purpose of clearly describing my invention.

What I claim is:

1. A sheet metal clamp comprising two members pivotally attached to each other intermediate of their ends, one end of each said member being extended into a narrower bite member, and resilient means carried by said device adapted to maintain said bite members in cross-position with respect to each other with their extremities extended outwardly from each other.

2. A sheet metal clamp comprising two members pivotally attached to each other intermediate of their ends, one end of each said member being extended into a narrower bite member, resilient means carried by said device adapted to maintain said bite members in cross-position with respect to each other with their extremities extended outwardly from each other and means whereby a movement of the biteless ends of said members toward each other will bring the extremities of said bite members to a common point.

3. A sheet metal clamp comprising two members pivotally attached to each other intermediate of their ends, one end of each said member being extended into a narrower bite member, resilient means carried by said device adapted to maintain said bite members in cross-position with respect to each other with their extremities extended outwardly from each other and means whereby a movement of the biteless ends of said members toward each other will move said bite members away from said cross-position with respect to each other.

HARTVIG A. DUNCAN. 

